Screw driver type tool



Jan. 11, 1944.

A. VOLZ SCREW DRIVER TYPE TOOL- Filed June 27, 1942 HM m I 1 v\\ a u INVE'N'TOR By 4/1 VOLZ J Wm A TTORNEY Patented Jan. 11, 1944 UNITED STATES PATENT oFFicE Arthur H. Volz, New York, N. Telephone Laboratories, York, N. Y., a corporation Y., assignor to Bell Incorporated, New of New York Application June 27, 1942, Serial No. 448,865

Claims.

This invention relates to a screw-driver type hand-tool suitable for use in rotating and determining the extent of rotation of a rotatable shaft.

The object of the invention is to provide improved means for rotating and determining the extent of rotation of a rotatable shaft not equipped with a turning knob or other hand hold.

A feature of the invention resides in the construction and arrangement of a dial and the means supporting the dial on the shank portion of the tool.

In the drawing:

Fig. 1 is a side view of the hand tool with the dial shown in two positions, one of the positions being shown in full line and theother in dot-dash lines;

Fig. 2 is'a front face view of the dial and its supporting means taken on the line 2-2 in Fig. 1 and showing the shank in cross section and the tool slightly rotated relative to the showing in Fig. 1;

Fig. 3 is a rear viewof the parts shown in Fig. 2 and shows also the blade end of the shank; and

Fig. 4 is an enlarged view partly in section of a portion of the shank-of the tool and the dial and the means supporting the dial on the shank.

In some electrical systems involving potentiometers, variable condensers and other devices employing a rotatable shaft, it is found advisable to'leave the usual turning knob off the shaft in order that the shaft may not bereadily rotated by someone not authorized to change the setting of the device. The shaft in such cases is usually mounted in registry with an aperture in a panel and a kerf is formed in the outer end-of the shaft to receive the blade end of a screw-driver. When rotation of the shaft is required a screw-driver type tool is inserted in the kerf in the shaft and the shaft is rotated by means of the tool. The ex tent of rotation required is sometimes quite critical and it'is difficult to determine the extent of rotation if an ordinary-screw-driver is used.

It is sometimes found necessary or advisable to replace a potentiometer or variable condenser in a system with another device of the same kind and to have the rotor of the new device rotated to the same extent as in the device replaced. There are also cases in which in makinga duplicate of a system found satisfactory, it is of considerable advantage to be able to readily determine the setting of a rotor shaft in a potentiometer or variable condenser employed in the former'set.

- "The present invention provides a'screw-dniver type tool suitable for use in rotating the rotor shaft of devices of the types above mentioned and for determining the extent of rotation of the rotor shaft.

'Ifhe tool as shown in Fig. 1 comprises a handle 5 and a shank 6 supported in and extending from the handle 5, the shank 6 being formed at one end toprovide a-blade 1 suitable for inserting in. a kerf provided in the end of a rotor shaft, not shown. The shank 6 is shown as being square in cross section but may be of different form except that there should be at least one flat surface extending longitudinally ,along the shank. In the form shownthere are four fiatsurfaces 8, :9, I9 and II on the shank 6.

A dial I2 with a large central aperture I3 formed therein is providedion thetool to facilitate determination of the extent of rotation of the tool or a rotatable shaft to which the tool ,is applied. The dial I2 is fastened by means of screws I4 to the rear surface of a block I5 which is arranged toslide alongthe shank 6 of the tool.

The block I5 is cup-shaped at the back and the dial I2 is secured to the rim portion I6 by means of the screws Hi. The front portion I! of the block I5 is frustoconical in form and a scratch mark I8 is made thereon to indicate how the dial I2 and the block t5 should be set relative to the run of the blade L. The front faceof the dial I2, as shown inHFig. 2, is provided with two annular sets of numbers. The outer set I19 of numbers may be compared with a mark on a panel of .an instrument board, not :shown, .to determine the extent to which a rotor shaft of .a potentiometer or other device has been rotated. The inner set .20 of numbers indicates the resistance in ohms of .a particular potentiometer at various settings of therotor shaft of the potentiometer. The dial I2 maybe replaced .by another dialdifferently marked but corresponding to another potentiometer, a variable condenser or other device it is desired to measure by means of the tool.

The block I5 is longitudinally bored at 2|, as shown in Fig. 4, to receive the shank l6 and is supported on the shank "6 by means of four L- shaped springs '22, 23, :Z land 25 which may 'be formed of sheet metal or otherfiatsheet material found suitable forthe purpose. Each L-shaped spring has a free leg portionextending into the bore M and in frictional engagement with the shank 6 and an aperturedleg portion clamped within the black 5 by means of: a screw =26, ,an apertured plate Z'I-and washer ZBWhicn-may be alock washer. The cup-shaped portion of the 2. block I is slotted to accommodate the secured leg portion of each L-shaped spring.

It will be seen by looking at Fig. 4 that the leg portion 29 of the L-shaped spring 22 is in fiat face-to-face frictional engagement with the flat surface 8 on the shank 6, and that the apertured leg portion 36 of the L-shaped spring 22 is set in a slot 3| in the block Hand is clamped against the inner surface of the base of the cupshaped portion of the block l5 by means of the screw 26, the plate 21 and the lock washer 28,

Also that the aperture 32 in the leg portion is larger in diameter than the threaded portion of the screw 26 so that the L-shaped spring 22 may be adjusted to such position that the leg portion 7 23 is in close face-to-face frictional engagement with the fiat surface 8 on the shank 6. The L- shaped spring 24 spring 22 and is adjusted so that one leg portion 33 is in close face-to-face frictional engagement with the flat surface of the shank 6. I"he aperturedleg portion 34 is set in a slot 35 in the block l5. 7 As shown in Figs. 2 and 3 there are two more L-shaped springs 23 and 25 to support the block [5 on 23 and 25 are constructed and supported like the spring 22, the'spring 23 having a leg portion 36 infiat face-to-face frictional engagement with the flat surface 9 of the shank 6 and having its apertured leg portion 31 located in a slot 38 in the block l5. The spring 25 has a leg portion 39 in flat face-to-face frictional engagement with the fiat surface II on the shank 6 and has its apertured leg portion 40 located in; the slot 4| formed in the block l5.

It will be seen, therefore, that the block I5 is frictionally supported on the shank 6 by means of the L-shaped springs 22, 23, 24 and 25 and may be moved along the shank 6 to various positions. Also that the leg portions of the L- shaped springs 22,23, 24 and 25 extending-into the bore 2| of the block l5 cooperatively form a hollow square to closely fit and encompass the shank 6 and that when the L-shaped springs 22, V

23,-24 and 25are properly adjusted relative to the shank 6 the'block l5 and the dial l2supported thereon cannot be easily turned relative tothe shank 6 and there can be no backlash between'the block and the shank .6. If an at tempt is made to rotate the block l5 and the dial l2 relative to the shank 6, spring tension will be developed in the L-shaped springs 22, 23, 24 and and this spring tension will bring the springs 22, 23, 24 and 25 into fiat face-to-face frictional engagement withthe fiat surfaces on the shank 6 and make the block I5 and the dial l2 resume normal position whenthe relative turning movement applied .to the parts is released.

The ferrule 42 on the handle 5 is secured-by means of a pin 43 to the shank 6 and will limit movement of the block l5 along the shank 6 in one direction. Movement in the opposite direction is limited by a stop comprising, a pin 44 provided on the shankB near the blade 1.

..When the tool is to be applied to a rotatable shaft, having a kerf in the end thereof, the user of the tool may slide the block [5 along the shank 6 to'the dot-dash line position shown in Fig. 1 so that he may readily see the blade I and the kerf in the. end of-the shaft to which applied. With the tool is required position for rotating the shaft the user of the tool may then slide the block l5 along the shank 6 to bring the dial l2 relatively close to a panel, not shown,but apertured to, accommodatethe shaft. Whenthe is a duplicate of the L-shaped the shank 6. The springs the tool is'being.

tool is turned to rotate the shaft the extent of rotation may be readily determined by observing the position of marks on the dial l2 relative to a scratch mark on the panel. If the dial I2 is marked in the manner indicated in Fig. 2 to show the resistance in ohms for a particular potentiometer at various rotated positions of the rotor shaft and the tool is applied to that particular type of potentiometer, the setting of the rotor shaft may be readily determined by observance of the position of the marks in the ring 20 relative to a scratch mark on the panel.

I am ware of the fact that it is not new in type tool and I do the art to provide a fixed dial on a screw-driver not broadly claim a tool of My screw-driver type tool is the fixed dial type tool and the purpose, since the on the shank and may that construction. an improvement over is more readily usable for dial is slidably supported be moved to various positions along the shank to enable a person to see the part to which the tool is being applied and to bring the dial relatively close to a panel after the tool is applied to the shaft.

What is claimed is:

1. In a screw-driver type tool comprising a shank to be rotated in rotating a shaft, a dial rotatable with said shank and mounted for movement along said shank, a fiat surface formed on and extending along said shank, and means supporting said dial involving a spring mechanically connected to said dial and having a fiat portion in fiat face-to-face relation with and frictionally engaging said flat surface and said spring operating to frictionally hold said dial against undesired movement lengthwise of said shank and operating to spring-resist turning said dial relative to. said shank. 2. In a screw-driver type tool comprising a shank to be rotated in rotating a shaft, a dial rotatable with said shank and mounted for movement along said shank, an apertured block supportingsaid dial, a fiat surface formed on and extending along said shank, a spring of sheet material supported in said block and supporting said block on said shank, and a fiat portion on said spring extending in close flat face-to-face engagement with said fiat surface and operating to frictionally hold said block against undesired movement along said shank and said spring operating to spring-resist turning said block rela tive to said shank.

3-. In a screw-driver type tool comprising a shank to be rotated in'rotating a shaft, a dial rotatable with, said shank and arranged for movement along said shank, an apertured block supporting said dial, a plurality of fiat surfaces formed on and extending'along said shank, and L-shaped springs supported'in said block and having flat portions cooperatively forming an opening for said shank and extending in close flat face-to-face frictional engagement-with-said flat surfaces on said shank and said springs cooperating to slidably hold said block on said shank and spring-resist turning said block relative to said shank. 4. In a screw-driver type tool comprising a shank to be rotated in rotating a shaft, a plurality of flat surfaces formedon and extending along said shank and providing oppositely dis posed fiat sides on said shank, an apertured block arranged for movement along said shank, aplurality of L-shaped springs formed of sheet material and adjustably mounted in said block and ad:- justable radiallyof said shank, leg portionson said springs arranged to cooperatively form a receptacle for said shank and extending in close flat face-to-faoe frictional engagement with said fiat surfaces, said springs operating to frictionally support said block on said shank and springresist turning said block relative to said shank, and an apertured dial mounted on said block.

5. In a screw-driver type tool for rotating a shaft and comprising a shank formed on one end to fit into a kerf provided on an end of said shaft, four flat surfaces formed on and extending along said shank, an apertured block arranged for sliding along said shank, four L-shaped springs of sheet material adjustably supported in said block,

means supporting said springs in said block, free leg portions on said springs extending into the aperture in said block, said leg portions being arranged to cooperatively form an opening for said shank and lying in fiat face-to-face frictional engagement with said flat surfaces, said springs cooperating to frictionally support said block on said shank and operating to spring-resist turning said block relative to said shank, an apertured dial secured to said block, and stop means on said shank te limit movement of said block along said shank.

ARTHUR H. VOLZ. 

